Systemic pesticides are pesticides that are absorbed by plant tissue and distributed throughout the plant by its vascular system. Systemic pesticides are widely used to regulate plant growth and to protect lawns, shrubs, foliage plants, and trees from diseases and from chewing and sucking pests such as aphids, whiteflies, mealybugs and soft scales. For example, pests ingest or come into contact with an insecticide and are eliminated when the pests feed on a treated plant.
Various methods are available for the application of systemic pesticides to plants. Spray application to foliage has been widely used, but has certain disadvantages, including weather dependence, short duration of control, and spray drift to the surrounding environment and the applicator.
Systemic pesticides may also be applied to soil by drenching or injection methods. However, many active ingredients used as pesticides, particularly those developed over the last twenty years, are sparingly soluble or insoluble in water. These active ingredients may be formulated for soil application as solid formulations such as wettable powders or wettable dispersible granules, or as aqueous suspensions or emulsion concentrates. Generally, the active ingredient is present as relatively large particles, or particles that tend to settle out or segregate upon dilution with water. After soil application of these formulations by drenching, broadcast spray, or injection, the uptake and distribution of the active ingredient throughout the plant may require several weeks or months. The soil application methods thus require treatment of the plants in advance of an expected pest infestation. Soil applications are generally therefore not useful for rescue treatments.
Other application methods for insoluble or sparingly soluble pesticides include trunk injections and trunk implants. These methods result in more rapid uptake and distribution of the active ingredient than soil applications, but require puncturing the trunk, which causes a wound to the plant and may cause long-term damage.
The present invention provides a method for application of a pesticide or other active ingredient to a plant that results in rapid uptake and distribution of the pesticide or other active ingredient without injury to the plant.